Automatic gear shifting mechanism



Feb. 13, 1940. T. F. CHL-:EK E1- AL 2,190,256

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Feb. 13, 1940. T. F.- cHEEK Er AL AUTOMATIC GEAR SHIFTING MECHANISM Filed April 9, 1935 9 Sheets-Sheet 9 Zozzzis 67. alger GMM/MM UNITED STATES? PATENT OFFICE# I AUTOMATIC GEAR-SHIFTING MECHANISM Tolbert F. Cheek, New York, and Louis G. Collyer, Congers, N. Y., asslgnors to Weite-Mignon Piano Corporation, Inc., Brooklyn, N. Y., a corporation of New York Application April 9, 1935, Serial No. 15,474

23 Claims. '(Cl. M -334) One of the important purposes of the invention ing a pneumatically operated power applying ls to eliminate the manually operated gearshiftmeans for connection with the gears to be shifted, ing lever commonly used in the shifting of the a series of valvular units having connection with gears of motor vehicles of the gasoline engine said power applying means and a plurality of type and to substitute for said lever a means interdependently operated control means which 5 which will automaticallyl shift the gears `from a coact in causing the said valvular units to be neutral position thereof to low and from low operated selectively to thereby variably control to second and'from second to high when the relative pressures to which said 'power' apthe clutch has been released for each of these plying means S subjected in effecting theseV- l0 shifts and which will operate in shifting from eral shifting operations. 10 lou/"to "second" and from second to high at These important purposes and others which those times, predetermined by the speed of the will appear t0 those familiar with vautcmatic vehicle, at which the gears to be intermeshed in gear shifting mechanisms, including the one t0 the said shifting operations are rotating at subwhich this application relates. are accomplished stantially the same speed and thus may be interin eachvof the several embodiments shown in the 15 meshed without clashing, 4 accompanying drawings and hereinafter described Another important purpose of the invention is in detail. Each of these several embodiments is to provide a gear shifting mechanism which comcharacterized in that it includes a master control prises pneumatically operable power applying means, a manipulative means having connection means for connection with the gears to be shifted with the master control means and including a Bil and a plurality of enacting control members member settable to a positionwhich predeteroperably associated with said power applying mines whether the shifting operation shall be means to variably regulate the relative pressures that resulting in fOIWaId 0l that resulting .in to which the letter is subjected in effecting the rearward movement 0f the vehicle, a pneumaticg5 several gear shifting operations and whereof one ally Operable means having Operating Cunnee- 26 of said members is settable by the operator of the tiOnS With an appropriate gear Shifting member vehicleinto a position for forward movement of 0f the transmission mechanism, for applying the vehicle for all speeds of the netter and anthereto the power which shifts the gears, a other of which is automatically operated under plurality 0f valvular control units having concontrol of the speed of the vehicle for the shift- IleCtOn With the DOWeI applying means and 30 ing operations from low into second and interdependently-operated means which are so from "second into high. associated with each other and with said manip- `Still another important purpose of the invenulative means as to cause said valvular units to be tion is to provide a gear shifting mechanism automatically operated selectively in accord with which comprises a pneumatically operable power the Shifts t0 be made and at DlOPel' times in 35 applying means and means for controlling the relation to the speeds of the vehicle. pneumatic pressures to which said power apply- The manipulatllfe means" herelnbefole Fe'- im.r means is subjected in effecting the various ferred to by which the direction of movement of shifting operations, including a control member the Vehle is predetermined, preferably comto which is scttable into a position in which it pre- Prises a IOtatlve bOdy member Which is Settable 4u determines whether the power applying means into different positions and is provided with shall be operated to effect forward., or reverse kmeans t0 COntlOl Various COHDeCtOIlS thlOU-gll movement of the vehicle,A as the `case may be, which other parts of the mechanism in turn are and which when once set for forward movement Controlled, including CnneCtiOnS aDDI'ODIte fOr 4&5 of the vehicle, coacts With other control means forward or reverse movement of the vehicle, as 45 in causing the gears to be automatically shifted the case may be, and for the shifting from one from low to "second and from second to gear ratio to another automatically in the forhigh without calling for any further attenward movement of the vehicle, Without further tion upon the part of the operator of the vehicle, setting of said member. This memberis moved it@ except the releasing of the clutch when the mechinto its different set positions by an appropriate 5l) anism forming the subject of this application for operatingv device which is within easy reach oi' patent is applied to transmissions of the type in the operator of the vehicle, as upon the dashwhich the clutch is not automatically released. board, for example. The said operating device A further important purpose of the invention may conveniently be in the form of a manually de is to provide a gear shifting mechanism comprisoperative lever and an appropriateI dial, or the like, having suitable indicia (as ,Neut., Forw., Rev. and 01T, for example) should be employed to designate the respective positions to which said body member should be set when the gears are to be in neutral position and when the connections are to be prepared for reverse or forward movement of the vehicle, as the case may be, or are to be entirely closed throughout. 'I'his means is hereinafter referred to as a preparatory means but said term applied thereto is not intended to be regarded as being restricted to the precise structure thereof hereinafter described in detail.

The pneumatically operable power applying means hereinbefore referred to comprises suitable operating members for connection with an appropriate gear shifting member of the transmission mechanism together with an operating means which is responsive to variations in the relative pressures on opposite sides thereof and acts to impart to said operating members the movements necessary in accomplishing the gear shifting operations. This operating means may be in the form of a piston reciprocatorily mounted in an appropriate chamber having air ducts connected to its ends on opposite sides of the piston, or may be in the form of a flexible diaphragm mounted in an appropriate chamber provided With such ducts. In operation, said gear shifting member of the transmission mechanism has movements in right-angular directions, one of said movements being to seat it in corresponding notches in longitudinally movable shift bars and the other to move said shift bars longitudinally, as is Well lmown to those familiar with the at present standard gear shifting mechanisms. It is preferred, in practice, to employ pneumatic members, either pistons or diaphragms, for accomplishing both of these movements, respectively, and in such case, the pneumatic member which is to move the gear shifting member of the transmission mechanism into and out of its seats in the respective shift bars is called upon to apply light pressure only, as compared with that applied to the other member, which accomplishes the longitudinal movement.

The master control means hereinbefore referred to includes a member which is operated to initiate the shifting operations when the clutch has been released. In those mechanisms in which the clutch is released and re-engaged under control of a clutch pedal, said master control member and clutch pedal are relatively so arranged that the master control member will be operated under control of said pedal. However, the presentI system is applicable in principle to mechanisms in which the release of the clutch is automatically effected and, additionally,

if so desired, the operation of accelerating the speed of the vehicle incidental to shifting operations likewise is automatically effected, thereby making all phases of the operations incidental to the shifting of the gears fully automatic when the preparatory means has been adjusted for forward or reverse movement of the vehicle and the engine has been started into operation.

The means which control the relative pressures to which said pneumatically operable members of the power applying means are subjected in effecting the various shifting operations includes a series of valvular units respectively having connections with the chambers containing said pneumatically operable members and which connections are controlled by selective operation of said valvular units. These valvular units are controlled, in part, by the preparatory means hereinbefore referred to and, in part, by other control members which coact with each other and with said preparatory means to cause the shifting of the gears to be so timed in relation to the vehicle speed that the shifts may take place only when the gears will not clash in going into mesh. One of the latter control mem'- bers is automatically adjustable by suitable means under control of the speed of the vehicle. A pump, either hydraulic or pneumatic, as preferred, having connection with the speedometer shaft provides a very desirable means for the operation of said control member. This control member is constructed to variably control the connections through which the before mentioned valvular units are selectively operated and said connections include two additional control members, one of which is controlled by a member of the power applying means and has a controlling influence upon the other, and the latter has connection with certain of the before mentioned valvular units, respectively. An additional valvular unit included in the system has connection with the preparatory means.

Reference has hereinbefore been made to pneumatic pressures to which the pneumatically operable members of the power applying means are subjected in effecting the various shifting operations. These pressures are preferably atmospheric and less than atmospheric, respectively. In other Words, in effecting operation of the said pneumatically operable members it is preferred to reduce the pressure of the air at one side of the same to below that of the atmosphere, whereupon air at atmospheric pressure will be effective to move said member. It will be understood that in certain of the .operations the reduction of the air occurs at one side of said member and at other times at the opposite side of said member. It should be understood, however, that it may not be wholly impracticable to employ airs of other relatively different pressures than atmospheric and less than atmospheric, respectively, such as, for example, airs of atmospheric and above atmospheric pressures or airs of different minus pressures'. However, the use of air having relatively different pressures at and above that of the atmosphere or relatively different pressures below atmospheric, involves complications in comparison with systems designed for air at atmosphericv and less than atmospheric pressures, since the latter may conveniently utilize the intake manifold of the engine of the motor vehicle in creating suction in the parts of the system in which air of less than atmospheric air is employed and simplifies the valvular arrangement for the inflow of air at atmospheric pressure. Accordingly, We have illustrated and will hereinafter describe in detail the system as designed to utilize the pressure of the outside air and suction induced by the engine without intending thereby to restrict the invention, considered in its broad aspects and as dened in appended claims, to the utilization of air having these particular relative pressures.

The entire system may be of pneumatic nature or said system may beof electro-pneumatic nature, as preferred. When the entire system is of pneumatic nature, all of the connections provide channels for the passage of air therethrough and the several control members are of corresponding nature and operate in controlling said channels. If the system is of electro-pneumatic nature the before mentioned power applyingmeans-will still be of pneumatic natureand the means, together with the several connections to the valve operating members of said units.

In the accompanying drawings certain preli'erred embodiments of the invention have been illustrated and these embodiments will be minutely described without, however, intending thereby to restrict the invention to the` details thereof since We are well aware that the invention may be otherwise and variously embodied without departing from the scope of the protection dened by appended claims.

In said drawings:

Fig. l is a side elevation, Fig. 2 is a top planview and Fig. 3 is an end elevation, of the casing which, in practice, encloses a standard automobile or truck transmission mechanism, for example, showing various parts of one embodiment of our gear shifting mechanism applied to said casing, Fig. 1 also showing the master control means and the preferred means for controlling the same;

Fig. 4 is a top plan view of the said casing, with the cap thereof removed, and shows the application of the several parts of our mechanism to said casing and to the shift bars of the transmission mechanism;

Fig. 5 is a front elevation of the operating device of the preparatory means and the dial associated therewith. employed in all illustrated embodiments of the system., for preliminarily arranging the connections for the automatic shifting of the gears into thosc appropriate for forward or rearward movement of the vehicle, respectively.

Fig. 6 is a detail side view showing the said operating device and dial, together with the member operated by said lever to selectively control certain pneumatic connections embodied in the mechanism;

Fig. 7 is a detail sectional View of said member as designed for the control of pneumatic connections in one illustrated embodiment of the invention;

Figs. 8 and 9 are sectional views, on a larger scale than the preceding figures, showing certain pneumatically controlled valve units for controlling the pneumatic pressures to which the power applying members are subjected in effecting the shifting of the gears, these two gures showing the valve members of the units in different relative positions;

Fig. l0 is a diagrammatic View, mainly in section, showing the entire system of pneumatically controlled valves and adjunctive devices in the neutral position of the gears and shows the position of the operating device of the preparatory means, at this time, but omits the clutch-release pedal and also the transmission mechanism;

Fig. 11 is a sectional representation, diagrammatic in its nature, and shows the position of the operating device of the preparatory means and of the pneumatically operated valve units and adjunctive means severally occupied by th'em in shifting from uneutral to low;

Fig. 12 is a view similar to Fig. l1, but shows the positions of the parts when the shift is from "low to "second";

Fig. 13 is a similar view showing the positions of the parts when the shift is from second to uhighn:

Fig. 14 is a similar view showing the positions of the parts when the shift is from neutral to reverse";

Fig. 15 illustrates, mainly in section. a modled embodiment of the'invention` and shows the neutral position of the severalvalves', as indicated by the dial and 'operating device of the preparatory means;

Fig. 16 is a detail representation of a pneumatic pump which may be employed for adjusting the valve which controls the times when shifting operations shall be performed to avoid clashing of the gears;

Fig. 17 is a detail representation showing pneumatically operable power applying members which may be employed instead of those illustrated in preceding figures;

Fig. 18 is a diagrammatic representation illustrating a preferred embodiment of electropneumatic nature, showing the parts in neutral position, as indicated by the operating device and dial of the preparatory means; and

Fig. 19 is a view of the rotative member of said preparatory means as seen from the side opposite that presented in Fig. 18.

Figs. a, il, 12a, 13a, 14s, 15a and 18a illustrate the setting of the indicator and its connected parts for the settings and positions of the parts in Figs. 10, 11, l2, 13, 14, l5, and 18, respectively.

A designates the gear housing of the transmission mechanism of an automotive vehicle, within which the transmission gears (not shown) are encased, and A1 designates the cover of said housing.

As is well known, the present standard gear shifting construction includes a slldable rectangular member a, Fig. 4. mounted to be movable laterally within a slot a1 for selective engagement with rectangular notches a2 and a3 in shift bars a4 and a5, each of which bars is movable rearwardly and forwardly for moving the gears into low, second, high", and reverse, as desired. Said member a at present is operated by a manually operated gear shifting lever which protrudes into the forward compartment of the vehicle but, by the present invention. this lever, as previously herein stated, is eliminated and the gear shifting member a of the transmission mechanism is automatically operated by our gear shifting mechanism.

The means employed illustrated in Figs. 1 4, 10-15 and 18 for applying power to the member a, in effecting the gear .shifting operations, includes a pair of chambers B and C, a pneumatically operated piston B in the casing B, a pneumatically operated piston C'` in the casing C, appropriate Aconnections between said pistons and the member a, for moving the latter in right angular directions, and suitable means for controlling relative pneumatic pressures to which said pistons are subjected in eiec'ting the gear shifting operations.

The casing B is preferably secured to one side of the housing A by suitable brackets b and the casing C is preferably secured to said housing by suitable brackets c. As shown in Fig. 4, the stern b1 of the piston B projects through one end of the casing B and is pivotally connected at b2 to a link b3 which in turn is pivotally connected at b4 to one end of one member d of a Z-shaped lever D, another of whose members, d1 is pivoted at d3 to one end of a bar E. This bar E is movably disposed Within a suitable guideway in the cover A', not shown in Fig. 4, of the gear housing A and has its end (designated E') opposite its pivot enlarged and provided with a rectangular opening e for the reception of the member a.

In lieu of the pistons B and C' and the particular chambers B and C in which said pistons are respectively mounted, pneumatically operated diaphragms mounted in appropriate chambers,

may be employed, as shown in Fig. 17,in which' the chambers are designated B100 and C100 respectively and the diaphragms are designated blo and C100.

The member a is selectively movable into the recesses a2 and a3 in the shift bars a'1 and a5, respectively, by the pistons C or diaphragm e100 and the meshing of the gears for the different speeds is effected by longitudinal movement of said bars transmitted thereto from the piston B or diaphragm 11100 through the connections just described to the member a, the use of either pistons or diaphragms as the pneumatically operable members of the, power applying means calling for no change with respect to the connections. 'Ihe lever D has its intermediate member d3 journalled in bearings d4.

In order that the piston C or diaphragm e100 may be operative to shift the member a selectively into the recesses a2 and a3 in the shift bars a4 and a5, respectively, said piston and likewise Y the diaphragm when the latter is employed in lieu of the piston, is provided with a stem, c1, which projects through an end wall of the chamber C or C100. This stem, as shown in Fig. 4, has its outer end pivoted at c1 to one end of a link c2 whose opposite end is pivoted, at to the corresponding side of the enlarged end E of the bar E. 'I'his movement of the member ais in a direction at right angles to the direction of the movement of said bar derived from the piston B or diaphragm b100.

In the particular embodiments shown in Figs. l-15, inclusive, but to the details of which embodiments this invention is not restricted, the preparatory means, which is adjustable to predetermine whether the shifting operation shall be from neutral into low or from low into reverse, is designated as a Whole by the letter H; the master control means, which has been referred to as being operative to initiate the shifting operations when the clutch has been released, comprises a valve I; the series of valvular units which are connected to the chamber on opposite sides of the pneumatically operated members of the power applying means are respectively designated K1, K1", K3 and K4. The interdependently-operated control means which coact with each other and with said preparatory means in controlling selective operation of said valvular units K1K4 comprise a valvular means, designated as a Whole by the letter J, a valvular unit K having connection with the valvular means J, a valvular means L which has a controlling influence with respect to the valvular means J through the valvular unit K and a valvular means, designated as a whole by the letter M, which is operated under control of the speed of the vehicle and has lconnection with the preparatory means and with the valvular means J and assures that the selective operations of the valvular units K1-K4 in effectv ing the shifting of the gears from low into second and from second into high shall occur only at those times in relation to the speeds of the "without clashing. This mechanism also includes a valvular unit K which has separate connections with the preparatory means and with a suction-inducing part of the engine of the vehicle. This particular valvular unit has a controlling inluence with respect to all of the valvular units K1-K5, as will be hereinafter explained. The structure of these several means incorporated in the system as arranged for pneumatic operation throughout, shown in Figs. 1-17, inclusive, will presently be described in detail and it may be here mentioned that the system, shown in Figs. 18 and 19, has means corresponding to those hereinbefore referred to although certain of said means have been designed to be operated electromagnetically, instead of pneumatically.

The preparatory means H employed in the pneumatic system illustrated in Figs. -1-l5, inclusive, includes a valve body h1 which is rotatively mounted in a casing h having a series of ports to which a series of ducts, respectively marked I-I0, inclusive, are connected. These ports are arranged in a line along the length of the casing and the latter has two additional ports designated Il and I2. The rotative valve body h1, as shown best in Fig. '7, has its circumference formed to provide a series of spaced ports respectively marked I3-20, inclusive, certain of which are respectively arranged to place the adjacent ends of corresponding pairs of the ducts adjacent said valve body into communication with each other for the shifting of the gears into low, into second and into high, and others of which (namely those designated l5 and I 6) are operatively related to the ducts 4 and 8, only, for the shifting of the gears into reverse, at which time they have direct communication with the atmosphere through ports Il and l2, respectively. This valve body h1 has an additional recess I4 which is not shown in Fig. 7, since it is arranged in the circumference of the valve body at a point diametrically opposite the recess I4 but is shown in Figs. l1, 12 and 13.

Rotative adjustment of said valve body h1 relatively to the casing h is effected by the operation of the lever h2 which is attached to the journal h3. This lever is arranged to be manually operated and is correlated with a dial, h4, having suitable designations as Rev., Neut., Forw. and Off to show the positions to which the valve body should be adjusted in preparing the connections for reverse or forward movement of the vehicle and also to show the position to which said valve body should be moved for adjustment of the gears into a neutral position and also for the complete closing of all of the connections. One end of the lever h2 is provided with a pointer h5 which cooperates with said designations in showing the position of the valve body Within the cylinder. This preparatory means H is mounted in any convenientl position within the vehicle, as upon the dashboard X, for example.

It should be understood that the invention is not conned to a preparatory means having the rotative valve member h1 even when of pneumatic nature and further is not conned to the use of a manually-operated operating lever, as the lever h2, but the Vdescribed valve member and lever are simple in structure and operate satisfactorily and for those reasons are greatly preferred.

The master control valve I is pivoted at one end (i1) to a block i having a channel i2, and is normally held in closed position by a spring i3. As here embodied it is moved to its open position,

aisance against the tension of said spring, by the clutchrelease pedal N in the clutch-releasing movement of the latter, said pedal having an arm n provided with a projection 111 whose path of movement is such that it engages .the free end of the valve I and presses the same rearward. This clutch-release pedal, as here shown, comprises an arm n2 additional to its arm n and is pivoted at the junction n3 of said arms. It is connected, in practice, with the clutch by usual means (not shown) and the free end of its arm n2 is provided with a foot piece n4 for convenience in operating it, as usual.

As previously stated, the pneumatic system includes a valvular means J, a series of valvular units `designated K-K5, respectively, a valvular means L, a valvular means designated as a whole by the letter M, means under control of the speed of the vehicle for operating the valve of the last mentioned member and a series of air ducts,`

including the ducts I-I, previously referred to, the passage of air through which is selectively controlled by the cooperative action of the valves 'of the several means herein referred to. The

preferred construction of these means will now be severally described, as follows:

The valvular means .I comprises a casing :i Within which is slidably mounted a valve body :il having a series of longitudinally aligned recesses which form ports, respectively marked 30, 3|, 32, 33, 34 and 35, through which the ends of certain ducts are selectively connected with each other in pairs, as hereinafter explained. It also has a separate recess forming a port 36 arranged oppor site the port 35. The casing also contains a spring 7'2 which is arranged to exert mechanical pressure against one end of said valve body. The end of the casing opposite the spring is provided with an atmospheric port or opening 3l and said easing is also provided near its opposite end with an atmospheric port 38 which is always in communication with the recess or port 3G in the valve body.

Each of the aforesaid series of valvular units K--K5 comprises three chambers respectively marked k, k1 and k2 and is provided with ports 22, 23, and 24 and a bleed hole 25. The chamber Ic of the valve unit K is preferably connected, through port 2li and duct O, with the intake manifold of the engine, as indicated.

As a matter of practical expediency, for the sake of compactness and simplicity of construction, these several valvular units are preferably mounted in a casing common thereto as shown in Fig. l and, in such case, the chamber lc'of the unit K is connected, through a port 26, with a, chamber k1 which is common to the several units Kl-Kf, inclusive. Each unit also comprises a valve member k3 having a stem 1c4 which extends through the port 23 of said unit and has its lower end engaged with a flexible diaphragm 1c' which separates the chambers k1 and k2 of the corresponding unit from each other. 'I'he valvemembers k3 of the respective units are mounted in the chambers 1c and open the corresponding ports 22 and 23 alternately. Each port 22 is an atmospheric port and is normally open. The port 23 of each unit is a suction port. It extends through the wall dividing the chambers Icand k1 from each other and hence said chambers have communicated with each other when the valve member k3 is in the position, shown in Fig. 9 in which it closes the atmospheric port 22 and opens the suction port 23 of the unit. Each port 24 leads to the chamber' k2 of the corresponding unit and each bleed hole 25 connects the chambers k:l and valve body, the latter having a channel 40 for registration with said port` 39.

The valvular means kM comprises a casing m.l having two series of oppositely arranged ports. It also comprises a valve body m1 having a port 4I which extends through its opposite sides and is adapted, by movement of the valve body to communicate selectively with corresponding parts of the two series. I'his port 4I is arranged about midway the length of the valve body and said valvevbody is provided with a separatelport, 42, which extends through one of its ends to the port 4I and opens into the latter. One end of the valve casing m is provided with a port 43 through which the port 42, and hence the port 4| also, have communication with the atmospherein all the operative positions of the valve body m1. Mounted in the end of the casing adjacent that rprovided with the port 43 is a spring m2 and mounted in the opposite end of the casing is a plunger or piston m3 which is connected to the corresponding end of said valve body by a stem m4.

In one embodiment of the invention, the end of the casing in which the piston or plunger m3 operates is connected with the exhaust side of a hydraulic pump M1 by a ltube 44. This pump is driven in consonance with the speed of the vehicle through the medium of ntermeshing gears M2 and M3, the former of which is mounted on an appropriate rotative part, as the speedometer shaft M4, for example, and the other of which is carried by the pump.

In this particular embodiment, M5 designates a liquid container or chamber having communication with the intake side of the pump casing through a tube and with the valve casing m. through a pipe 46 which enters said casing at one end of the valve body m1. A branch connection between the pipes 44 and 46 is provided by a `pipe 4l. 48 designates an adjustable needle valve and 49 the seat for the pointed end of said needle valve. These are arranged at the junction of the pipes 44 and 41 and control, by adjustment of the needle valve, the amount of liquid passing into the casing m, thereby regulating the pressure exerted upon the piston or plunger m3 to cause movement of the valve body m1 in accord with the speeds of the vehicle predetermined for such movement. 'I'he pipe 46 which directly connects the valve casing m with the container M5 acts as a drain through which any liquid which may escape past the piston or plunger m3 is returned to said container, and a branch connection 50 isv provided through which liquid is returned to the pipe 41 and thence through pipe 46 to the container M5 upon movement of piston m3 to a position beyond the branch `connection 5l). The liquid preferably utilized in this part of the shifting mechanism is oil, the reason for which is apparent.

Referring now particularly to Fig. 10, which shows the positions of the valves with respect to the connections when the gears are in neutral position, it will be noticed:

That the duct extends from the corresponding port in the valve casing h of the preparatory means H to the channel i2 of the block 1'; that the duct 2 extends from the corresponding port in said valve casing to the chamber k2 of the valve unit K; that the duct 3 extends from the corresponding port in said casing h to the valve casing m and enters one side of the latter; that the duct 5 extends from the corresponding port in the valve casing h to the valve casing m and enters the latter at the same side as, but in a spaced relation with respect to, the duct 3 and has a branch 5aL which enters said valve casing m at a point diametrically opposite the entrance of duct'3 into said casing; that the duct 1 extends, from the corresponding port in said casing h, directly to the casing m and enters the latter at a point adjacent the duct 3 and on the side of said duct opposite the duct 5; that the duct 9 has two branches 5|a and 9b which enter the casing m at points respective diametrically opposite the duct 5 and the end of the duct 1.

It will also be noted that the ducts 4, 6, 8 and I0 extend from the casing of the preparatory means H to the casing i of the `control means J and enters the latter at different places along the length of the same and into operative relationship with different ports in the valve body il, respectively. Thus, it will be seen that the duct 4 extends into operativerelationship with the port 32, the duct 6 extends into operative relationship with the port 33, the duct 8 extends into operative relationship with the port 34 and the duct I0 extends into operative relationship with the port 35.

It will further be noticed that the corresponding chambers k2 of the control units K1, K2, K3 and K4 are connected with the interior of the casing 7' of the valved means J by ducts respectively designated 5|, 52, 53 and 54. The duct 5| enters said casing i at a place which is so positioned with respect to the corresponding end of the duct 4 and the port 32 in the valve body :i1 that both corresponding ends of said ducts 5| and 4 communicate with each other through said port 32 when the valve body jl is in one of its positions. This duct 5| is tapped by one end of a branch 5| e whose opposite end enters the casing at a place which is operatively related to the port 3| in the valve body i1. The duct 54 enters the casing :i at a place adjacent one end of the valve body :i1 and is tapped by a branch 54a which enters said casing j at a` place adjacent the other end of said valve body and is operatively related to the port 30 in the valve body. The chamber 1c of the valve unit K5 is connected with the corresponding end of the casing g'by a duct 55.

The casing j is also connected with the casing l forming part of the valved means L by a duct 56 one end of which enters the casing y' near one end of the latter and extends thence into a position in which, as shown, it registers with the port 39 in the casing Z. This duct 56 is connected by a branch duct 56 with the chamber k2 of the valve unit K5. Two additional ducts, 51 and 58, are alsol connected to the casing l and connect the'latter with the valved means J-the duct 51 being arranged on one side of the duct 56 and entering the casing :i in a position operatively related to the port 3| and the duct 58 entering the casing l on the side of the duct 56 opposite the duct 51 and entering the casing 9 at a place which is operatively related to th port 30 in the valve body d1.

The chambers 1c of the respective valve units K1 and K4 are connected with the opposite ends b* and b of the piston casing or cylinder B, that is, on opposite sides of the piston B1, by ducts 6U and 6|, respectively, and the chambers k of the units K2 and Kll are connected with the opposite ends c* and c* "YY of the piston casing or cylinder C on opposite sides of the piston C by ducts 62 and 63, respectively.

Correlation of the parts in neutral position It will be noticed that when the lever h2 of the preparatory means" H is in the neutral position shown in Fig. 10 and the valve I is closed: the valve members k3 of the several valve units K-K5 will be in a position in which the several chambers 1c of said units are in communication with the atmosphere through the ports 22 and the chamber k2 of the valve unit K5 is in communication with the atmosphere through the branch duct 56', duct 56, port 39 and port 40; the end portions b* and b" and c* and c" of the casings or cylinders B and C on opposite sides of the pistons B and C' in said cylinders are in communication with the atmosphere through the ducts 60, 6|, 62 and 63 and the chambers k and ports 22 of the valve units K1, K2, K3 and K4; and the chamber k1 common to the several ducts Kl---K5 is in communication with the atmosphere through the port 26, chamber k and port 22 of the valve unit K. At this time also the Valve body m1 of the control means M is in the position in which its port 4| is in registration with the duct 1 and the branch 8b of the duct 9, and the valve member il of the control unit J is in the position in which its port 30 is in communication with the ends of the duct 58 and branch duct 54a, its port 3| is in communication with the ends of duct 51 and branch duct 5|a, its port 32 is in communication with the duct 4, its port 34 is in communication with the duct 6, its duct 34 is in communication with the duct 8, its port 35 is in communication with the duct |0 and its port 36 is in communication with the atmosphere through port 38.

Operation As a preliminary step in the shifting of the gears into low the lever h2 of the preparatory means H is moved to the position in which its hand 11.5 points to ForW., thereby moving the valve body h1 to the position in which its port I4 (Fig. 11) registers with ducts i and 2, its port I9 registers with ducts 'l and 8 and its port 20 registers with ducts 9 and I0. At this time also the port |1 registers with ducts 3 and 4 and the port I8 registers with ducts 5 and 6 in order that the Ways may be prepared for subsequent shifting operations from low to second and from second to high, the shifting operations into low calling only for the ducts 'l-ll), inclusive. In short, adjustment of the valve body h1 to the position corresponding to ForW. on the dial is the only adjustment thereof necessary in effecting all the shifting operations for forward movement of the vehicle. I

When the engine is started, the pressure of the air in chamber k1 of the valve unit K is immediately reduced by the suction created in duct O and, since the chamber k2 of said unit K has communication with said chamber k1 through the bleed hole 25, the pressure of the air in said chamber k2 and also in the ducts and 2 is similarly reduced. If the engine is started before the lever h2 has been adjusted for forward movement of the vehicle, communication between ducts I and 2 is established through the port I3 5 and is interrupted in the adjustment of the said lever to the said position, but this interruption is momentary only since communication is immediately re-established through the port M', shown in Fig. 1l.

m Upon the opening of the master control" valve I there will be an inrush of air at atmospheric pressure through the channel i2, duct l, recess I4' and duct 2 into the chamber k2 of the valve unit K and since the chamber k1 of said l5 valve unit is, as already stated, under suction at this time, the corresponding valve body k3 will be instantaneously moved to the position in which it closes the corresponding atmospheric port 22 and opens the corresponding suction port 25,

30 thereby placing the chambers k and k1 of said valve unit (K) in communication with each other. As a. result of this movement of the valve body k3 of the unit K, the chamber k1 common to the several valve units Kl-K5 is placed under suc- :5 tion. Inasmuch as the chamber k2 of the valve unit K5 is incommunication with the atmosphere at this time, (through the branch duct 56', duct 58, port 39 in casing l and port 40 in valve body Z1) it follows that the valve body k3 of said unit 30 K5 will be moved to the position in which the corresponding chamber k is closed against the atmosphere and opened to suction. Since chamber k of valve unit K5 is in communication, through duct 55, with one end of the casing a' g5 of the valved means J, the pressure of the air in said end will now be reduced sufiiciently to enable the atmospheric pressure, admitted through vport 31 and acting upon the end of the valve body gi opposite the duct 55, to be eiective to o move said valve body longitudinally to the position shown in Fig. 11, in which its port 35i registers with the ducts t and 53 and its port 35 registers with the ducts IEl and 5t. Said port 3d is in communication with the atmosphere, 5 through the port i3 in the casing m, ports 42 and li in the valve body m1, duct l, port i9 in the valve body h1 of the preparatory means H and duct il; and port 35 is in communication with the atmosphere through said port 433 in the .o casing m, ports l2 and di in the valve body m1,

branch duct 9b, duct 9, port 26 in the valve member h1 of the preparatory means H and duct i8. Since at this time the port 34 has opened communication between ducts B and 53 and port 35 a has opened communication between ducts l and d, it follows that the chambers k2 of the respective valve units K3 and K4 are opened to the atmosphere, whereupon the respective valve menibers k3 of said valve units will close the corre- 0 sponding atmospheric ports 22 and open the corresponding suction ports 23, thereby placing the end portions cam and bt" of the respective piston casings or cylinders B and C under suction. At this time, the end portion c* of the casing or cylinder C is in communication with the atmosphere through the atmospheric port 22 and chamber 1c of valve 'unit K2, and the duct 62, and the end portion b* of the casing or cylinder B is in communication with the atmosphere through 0 atmospheric port 22 and chamber 7c of valve unit K1 and the duct til: hence, preponderating pressure in said end portions c* and b* causes 'movement of the pistons C and B in the directions of the arrows (Fig. 11) and operates the g member a. (Fig. 4) in the right angular directions required in bringing about the intermeshing of the low gears (not shown) ci' standard transmission mechanisms. In this operation, the piston C' exerts pressure upon the side of the enlarged end E' of the bar E through its 5 stem c and link` c2, thereby imparting lateral movement to said end and causing the member a to be seated in the recess a3 of the shift bar a5, and the piston B' moves its stem b1 outward, thereby imparting corresponding movement to the member d oi the Z-shaped lever D, which lever turns about its axis at d3 and moves the bar E longitudinally within its guideway in a direction substantially the reverse of that of the piston B', and hence moves said shift bar a5 in 15 the direction which engages the low gears with each other. ,H

It will be noticed that upon movement of piston B the valve body l1 is correspondingly moved, through lever D, arm Z3 and rod l2, the movement 20 of said valve body Z1, however, being of less extent than that of the piston B', since the connections are so proportioned that the movement of valve body l1 is such that only one duct 56,

5l or 58 is open to atmosphere at any one time. 25

It will also be noticed that this valve body lx is in central position and the chamber k2 of the valve unit K is open to atmosphere through ducts 55 and 56 and ports 39 and 40 of the valved unit L, when the gears are in neutral position, as here- 80 inbefore stated, and that while the gears are being moved to low speed position said valve body Z1 will be moved in the direction indicated by the arrow in Fig. 10, whereby duct 56 will immediately be closed to atmosphere through ports (lll and 39, but port 3B of this valved unit J will have been moved into registration with the corresponding end of the duct 56 by the previously described movement of valve body i1 of said unit (J) and hence valve k3 of valve unit K5 will be retained in raised position until the shift is completed.

The valvemember Z1, the lever D and the pistons B and C remain in the position to which they have been moved in shifting from neutral s to low until the Ashifting of the gears from low to .second has been started. All of the valve members 7c3 of the units K, K3, K4 and K5, and also the valve member il of the control means J, however, are automatically returned to the neutral position shown in Fig. 10 as soon as the master control valve I is closed, since the closing of said master control valve closes com` munication of the chamberjc2 of valve unit K with the atmosphcrawhich results in a balancw ing ci the pressures on opposite sides of the diaphragm k1 in said unit (K), whereupon the corresponding valve member 7c3 returns to its position in which it opens the corresponding atmospheric port 22 and closes the corresponding 60 suction port 23, thus opening the chamber k1 common to the several valve units K1-K5 to the atmosphere, through the port 26 and the charnber lc of valve unit K, and thereby balancing the pressures (atmospheric) on opposite sides of the 65 diaphragm k1 of valve unit K5 and permitting the corresponding valve member ki* to move to the position in which it opens the corresponding atmospheric port 2.2 and causes air at atmospheric pressure to enter the corresponding chamber 1c a@ and flow through the duct to the corresponding end of the casing a' of the control means J, thereby bringing about a counterbalancing of the pressures on opposite ends of the valve member 7'1 in said casing and making the spring i2 eifecw tive to restore said valve member to its former position.

During the preceding operation oi shifting the gears into low the vehicle of course is stationary and the pump Ml is not operating but when movement of the vehicle has commenced with the low gears in intermeshing relationship with each other, said pump begins to operate and in its operation draws the liquid, preferably oil, from the chamber M into the inlet side of the pump', through the pipe 45, and discharges said liquid from the outlet side of the pump, through the pipe 44, against the piston m3, in amounts controlled by the.needle valve 48.

Acceleration o1 the speed of the vehicle causes a corresponding increase of the speed of the pump, whose effect with relation to the piston m5 is so regulated by the needle valve 48 that by the time the speed of the vehicle has attained that at which the shifting into second maybe accomplished without clashing of the gears, suficient pressure will have been createdat the end of the pipe 44 between said needle valve and the casing m, and hence upon the corresponding side of the piston m3, to move the vvalve member m1 from the position in which the port 4| of said member is in registration with duct 1 and with branch duct 9b of duct 9 to the position in which its said port 4| is in registration with the duct 3 and branch duct 550i duct 5. l

If now, the master control valve I be again opened, air at atmospheric pressure will again rush into the chamber k2 of Valve unit K, thereby again operating the valve member la?, of said unit to again place the chamber k1 ,common to the several units K1-K5 under suction. It will be remembered that the valve member l1 of the control means L was moved to the position in which its port 40 is out of registration with duct 56 by the previous movement of the piston B' in shifting the gears into low and said valve member is in the latter position at the beginning of the operation of shifting the gears into second. Hence, the opening of the master control valve I which initiates the shift from low into Second does ot immediately change the position of the valve member k3 of the unit K5 from that in which it is shown in Fig. 10, namely, from the position in which it opens the corresponding atmospheric port 22 and closes the corresponding suction port 23. p

Duct 51, however, has been opened to the atmosphere by the described movement of the valve member Z1 and hence air at atmospheric pressure will flow through said duct to the port 3| in the valve member-jl, the said valve member being still in the position shown in Fig, 10. From said port 3|' the air ows through the branch duct 5| and the duct 5| into the cham-V ber k2 of the valve unit K1. At this time the chamber k1 of the saidvalve unit is under suction and hence the corresponding valve member k3 will be moved to close the corresponding atmospheric port 22 and open the corresponding end portion b* .of the piston casing or cylinder B to suction through the corresponding chamber 7c and duct 60. Since at this time the end portion bi* of said casing or cylinder B is under atmospheric pressure, through the chamber k of the valve unit K4 and duct 6|, it follows that the piston B' will be moved toward the suction side of the said casing or cylinder, thus imparting corresponding movement to the member a of the shifting mechanism, through the bar E and the previously described connections between said the valve unit K5 is now moved to close the corre- A sponding atmospheric port 22 and open the corresponding suction port 23. The pressure of the air in the end 'of the casing :i of the control means J opposite the atmospheric port 31 in said casing consequently is reduced by suction from chamber lc of the valve unit K5 through duct 55. As

the result of' this, the valve member i1 of the control means J is again moved toward the thus exhausted side of the casing by the atmospheric pressure exerted on the opposite end of said valve member, into a position in which its port 32 is in communication with the'chamber k2 of the valve unit K1 through the duct 5|. Since this port 32 isopen to the atmosphere through duct 4, 'port I1 and the valve member h1 of the preparatory l means, duct 3 and portsl 4| and 42 of the valve member m1, it follows that at substantially the same instant communication of chamber k:i of valve unit K1 with the atmosphere through duct 5|, port 3| and duct 51 was broken, communication `of said chamber k2 with the atmosphere is again re-established, but this time is through the described connections between the port 32 and said chamber k2 and the atmosphere, and the latter communication continues throughout the remaining phase of the operation of said piston B' in which the duct 56 is open to the atmosphere and both pistons are operating in completing the shift from low into second.

The piston C is operated at aproper time in relation to the movement of the piston B', as follows:

'I'he movement of the valve member which placed its port 32 in communication with the chamber k2 of valve unit K1 through duct 5|, also placed its port 33 in communication with the chamber k2 of valve unit K2,Athrough duct 52, without closing communication of said port with duct 6. Hence, air at atmospheric pressure is admitted to the chamber k2 of valve unit K2- through ports 42, 4| in valve member m1, branch duct 5a, duct 5, recess I8 in valve member h1, duct 6, recess 33 in valve member 71 and duct 52-and acts to cause the corresponding valve member k5 to move to the position in which it closes the corresponding atmospheric port 22 and opens the corresponding chamber 1c to the corresponding suction chamber k1, thus placing the corresponding end portion c* of the Vcasing or cylinder C under suction. Since the end, portion c* of said cylinder is under atmospheric pressure at this time, through chamber k of valve unit K5 and duct 63. it follows that the piston C will be forced by the preponderating (atmospheric) pressure in the said end portion 0** to move the piston C' toward the end portion c* and thereby move the member a of the transmission mechanism into the seat a2 of the shift bar a4 for the remainder of the shifting operation into second".

When the shift into second has been completed, the master control valve I is again closed, whereupon the valve members k3 of the several valve units K, K1, K2 and K5 which were operated in effecting said shift, and also the valve member 7'1, return to their respective original positions, but the'remaining valves (namely, h1, m1

and l1) and also the pistons B' and C remain in the positions to which they were moved in the previous operation.V

In order to initiate the shift from second to high the clutch is released and the master control valve I is again opened causing air at atmospheric pressure again to rush' into the chamber k2 of valve unit K and the corresponding valve member k3 to close the corresponding at mospheric port 22 and open the chamber k1 common to the several valve units K1K5, to suction. When the speed of the vehicle and the speed of the pump Ml has been accelerated to that at which the shift into high" may be made without clashing of the gears, predetermined, as before suggested, by the setting of the needle valve 48, the valve'member m1 will be moved to the position in which its port 4| registers with the duct 5 and branch duct 9H. When the valve member 9'1 is in the position shown in Fig. 10,

e the duct 5 is in communication with the port 33,

through the port I8 in the valve member h1 and the duct 6, and the branch duct 9 are in communication with the port 35 of said valve member il through the duct 9, port 20 in the valve member h1 and the duct I0. At this time, the ducts 5|-54 are closed.

As soon as the -pressure of the air in the chamber k1 common to the several valve units K1-K5 has been reduced, as the result of the described operation of the valve member k3 of the unit K, the valve member k3 of the unit K5 will be operated to close the corresponding atmospheric port v 22 and to open communication of the corresponding chamber lc with the suction chamber k1, since the chamber k2 of the latter unit (K5) is under atmospheric pressure through the branch duct 56', duct 56, port 40 in Valve member Z1 of unit L and port 39 in the casing member of said unit L. Hence, the pressure of ythe air in the corresponding end of the casing member of the unit J is reduced to below that of the atmosphere and the valve member :il of said unit is forced by the preponderating atmospheric pressure at the 0pposite end of said member to the position in` which its port 33 is in communication with ducts 6 and 52 and its port 35 is in communication with ducts I0 and 54. It will thus be seen that as soon as the valve member 9'1 has been moved to the latter position the valve members k3 of the respective units K2 and K4 will be moved to their positions in which they close the corresponding atmospheric ports 22 and open the corresponding ends C* and b** of the casings or cylinders C and B to suction from the chambers lc of said valve units through the ducts 62 and 6|, respectively. Since the end portions of the casings or cylinders on the opposite sides of the pistons B and C' are at this time under atmospheric pressure, through the ducts and 63 and the chambers k of the respective valve units K1 and K3 it follows that the pistons B' and C will be moved in the directions shown by the arrows Fig. 13 and by their said movements will cooperate, through their described connections with the member a of the transmission mechanism, in the shifting of the gears from "second into high.

As soon as the shift from second to high has been completed, the master control valve I is closed thus, as before explained, cutting off communication between the chamber k2 of the valve unit K with the atmosphere andpermitting the valve member k3 of said unit to move to the position in which the corresponding atmospheric port 22 is opened and the corresponding suction port 23 is closed, thereby again opening communication between the chamber k1 common to the several valve units K1-K5 and the atmosphere through the port 26, and the chamber lc and atmospheric port 22 of unit K. This in turn results in movement of the valve member k3 of unit K5 to the position in which the corresponding atmospheric port 22 is opened and the corresponding suction port 23 is closed, thereby counterbalancing the atmospheric pressure on opposite ends of the valve member :il by admitting atmospheric air into the corresponding end of the casing y' through the port 22 and chamber k of valve unit K5 and duct 55, thus causing said valve member 71 tobe moved to its initial position by the spring i2. In this movement of the valve member f1 the ducts 52 and 54 are closed to the atmosphere and hence the valve members k3 of the units K2 and K4 will move to their positions in which the corresponding atmospheric ducts 22 are opened and the corresponding suction ducts 23 are closed, thereby restoring the atmospheric balance of pressures in the chambers c* and 0** of the cylinder or casing C and in the chambers b* and b in the cylinder or casing B.

The several parts mentioned remain in this condition throughout the entire movement of the vehicle in "high gear, since any increase of the speed of operation of the pump M1, resulting from corresponding increase in the speed of operation of the vehicle, does not increase the pressure of the liquid upon the piston m3, the increase in the speed of flow of the liquid being taken care of by the needle valve 48 which has been set to by-pass the liquid through the ducts 41 and 46 back to chamber M5 and also to cause the drainage back into said chamber, through the branch duct 50 and the upper end of duct 46, of any liquid in the casing m which would create excessive pressure upon said piston. The pressure of the liquid upon thepiston m3 is thus maintained substantially constant, regardless of the speed of the vehicle, when the gears are in high and until the speed of the vehicle, and consequently that of the pump, drops to the point at which the pressure of the liquid exerted upon the piston 1n3 falls below that at which the valve member m1 was moved to its position in which the shift from "second to high was made. In such case, the pressure of the spring m2 becomes effective to move said valve member m1 to re-establish communication of the port 4l with duct 3 and branch duct 5a whereupon, when the clutch is again released and the master control valve I is again opened, the mechanism will be operated to shift the gears automatically back into "second. In this movement, the piston B will be moved in the direction opposite that in which it was moved in shifting from second to high and the pressure in the end portion 0** of casing or cylinder C will urge piston C in the same direction as when the shift was made from second to high for the reason that member a must be maintained in notch a2 of shift bar a4 in the movement of said bar to shiftthe gears into both second and "high. Similarly, when the speed of the vehicle drops to the point at which the pressure on the piston m3 is insuilicient to maintain said piston in the position in which its port 4I is in registration with duct 3 and branch duct 5a and the spring' m2 becomes effective to move said piston to its initial position, the mechanism will operate automatically, upon release of the clutch and the opening of themaster control valve I, to shift the gears from second to low, the piston B' in this case moving in the direction opposite that in which it was moved in shifting from low to second. When it is desired to stop the vehicle with the gears in neutral the lever h2 should be turned to the position in which the hand h hereof points to Neut. on the dial h4, after which the master control valve I is opened upon releasing the clutch ln-a manner heretofore explained. Atmosphere will now be admitted to chamber k2 at valve unit K through port i2, duct I, recess I3, and duct 2 whereupon valve k3 of valve unit K will close port 22 and open port 23 thus placing chamber k1 common to valve units K1--K5 under suction.

It is tobe here noted that when valve member h1 has been moved to the Neut. position communication of chamber k2 of each of valve units Kl-K5 with the atmosphere is cut off since no ports in valve member h1 are in a position to place ducts 3, 5, 'I and 9 in communicationY with ducts 4, 6, 8 and Il)Y respectively. Atmosphere may however be admitted to chamber k2 of either of the valve units K1 or K4 through valves L and J and interconnecting ducts 51, 5Ia and 5I or ducts 58, 54*i and 54.

Thus if the gears are in low at the time the valve h1 has been moved to Neut.l position the valve member l1 will be to the right of its central or neutral position indicated in Fig. 10 and accordingly duct 51 will be in communication with atmosphere through valve casing l which will admit atmosphere to chamber k2 of valve unit K1 through ducts 51, 5Ia and 5I and valve k3 of this unit will accordingly close port 22 and open port 23 andA thus admit suction to end portion b* in cylinder B at which time atmosphere will be admitted to end portion b" in cylinder B and piston B' will be moved to the left (Fig. 10) to a position in which channel 40 in valve Z1 registers with port 39 and duct 56.

If on the other hand, the gears be in Rev. when valve h1 has been 'moved to Neut. position valve l1 will be to the left of the position indicated-in Fig. 10 and duct 58 will be open to atmosphere through valve casing l. This will admit atmosphere to chamber k2 of valve unit K4 through ducts 58, 54a and 54 and thus valve 7c3 of this unit Will close port 22 and open port 23 and thus admit suction to end portion b** and thus due to the admission of atmosphere to end portion b* through valve unit K1 piston B will be moved to the right (Fig. 10) to a position in which channel 40 again registers with port 39 and duct 56.

It will be noted that piston C', is not influenced in the above described movements since in going into Neut. or unmeshing of the gears the shift bars'a.4 or a5 need only be moved longitudinally in the direction depending upon the position of the gears before going into Neut.

When the vehicle is to be parked the lever h2 should be turned to the position in which the hand h5 points to Off in which position communication of ducts I, 3, 5,'1, 9 and 2, 4, 6, 8 and IIJ respectively iscut off through valve h1.

It is preferred, in practice, to provide an inconspicuous and appropriate locking means for preventing the movement of said lever to an operative position by an unauthorized person.

In going from neutral to reverse, the operator rst turns thelever h2 to the position in which the hand points to Rev., thus correspondingly turning the valve member h1 of the preparatory means H to the position in which the ports I5 and I6 have communication with the atmosphere through the ports II and I2 ln the casing h and respectively register with the ducts 4 and I. At this time, the' ducts I and 2 have communication with each other through port I`4 in said valve member h1, as shown Fig. 14. Thus, as soon asY the engine has been started, the chamber kl of valve unit K will be exhausted so that upon the opening of the master control valve I the valve member k1i of said valve unit (K) will be operated to close the corresponding duct 22 and open the chamber k1 common to the several valve units Kl-K5 Yto suction, all as previously explained. Since the ducts 4 and 8 were opened to the atmosphere by the adjustment of the lever h3 to Rev., it follows that as soon as the chamber k1 commonV to the several valve units Kl-K5 is under suction, valve 71 will be moved in the manner heretofore described and thus put ports 32 and 34 therein in communication with ducts 4 and 5I and 8 and 53 respectively, whereupon valve members k3 of the respective valve units K1-K3 will be operated to close the corresponding atmospheric ports 22 and open the cor'- responding suction ports 23, since at this time air at atmospheric' pressure reaches the chamber k2 of valve unit K1 through ports II and I5, duct 4, port 32 and duct 5I and air at atmospheric pressure reaches the chamber k2 of valve unit K3 through ports I2 and IB, duct 8, port 34 and duct 53. The closing of the atmospheric port 22 of chamber lc of valve unit K1 results in the exhausting of the air in the end portion of the chamber b* of the cylinder or casing B and the closing of the atmospheric port 22 of Vthe valve unit K3 results in the exhausting of the air in the end portion 0** of the casing or cylinder C. Thus, the pistons B and C' are moved in the directions of the arrows shownY in Fig. 14 and impart corresponding movement to the member a of the transmission mechanism through the connections hereinbefore described, thereby placingA the gears into intermeshing relationship appropriate for rearward movement of the vehicle. When the gears have been thus intermeshed, the master control valve I is again closed, whereupon the valve member k3 of the valve units K1 and K3 return to their former positions in which the corresponding atmospheric ports 22 are opened and the corresponding suction ports 23 are closed. It will be understood that when the end portions b* and 0** of the caslngs or cylinders B and C are under suction, the end portions bM and c* contain air at atmospheric pressure, thus causing the pistons B and C' to move, and that when, as the result of the closing of the master control valve I both end portions of each of cylinders B and C are in communication with the atmosphere and said pistons B Vand C' will be subjected to counterbalancing (atmospheric) pressures and will remain in the positions to which they have moved in effecting intermeshing relationship of the gears for rearward movement of the vehicle until the lever r11.2 has again been adjusted to Neut. Y

VYFrom the foregoing it will be apparent that all the labor of manually shifting the gears is eliminated, since all the movements imparted to the transmission mechanism by said manually operated lever are automatically accomplished by the hereinbefore described mechanism. It will also be apparent that clashing of the gears which not only is unpleasant to the ears but also shortens thelives of the gears is avoided. The operator of the vehicle is only Ato required, according to the described embodiment of the invention, to release the clutch between each shifting operation, the clutch pedal being arranged to open the master control valve I and to permit said valve to close automatically upon release oi the pressure imposed by the operator on said clutch pedal. tional operation which the driver of the vehicle need perform is the preliminary adjustment of the lever h2 to predetermine whether the movement of the vehicle shall be in a forward or rearward direction. When this lever has been once set for forward movement of the vehicle the shifting operations into low" and into second and into high are wholly automatic when the clutch has been released for each of these operations.

The embodiment of the invention shown in Fig. 15 is similar to the embodiment illustrated in Figs. 1-14 except for changes in certain of the details which do not affect the principle of operation. Thus, it' will be noticed that the valve, marked 7'11, which corresponds to the valve .il of the previously described embodiment, is

formed with only four ports, respectively marked 30', 3|', 32' and 33', which correspond to the ports 30-35 in the previous embodiment, and with an atmospheric port 35' which corresponds to the ports 36 and 38 in said previous embodi@ ment. Moreover, `this valve, instead of being slidably mounted in a guiding and supporting case having an atmospheric port in one of its ends and its opposite end portion closed and provided with a spring engaging the corresponding end of the valve is slidably mounted in and guided by a channeled supporting block 7" hav-v ing ilanges 7'* extending toward each other and upon which the bottom surface of the valve rests, and said block is open at both of its opposite ends and one end of the valve is engaged by a spring i12 and the opposite end of the valve is connected by a stem :i13 to a piston 514 which operates within a chamber 15 whose end adjacent the valve is open and whose opposite end is closed.

In this particular embodiment the valved control means, marked L10, is functionally similar to but structurally somewhat dissimilar from, the corresponding part L of the previously described embodiment. Its valVe 111 travels upon the outside of a supporting block 11 in a guided relation with said block, being formed to substantially embrace the block, as indicated. This valve is provided with a port 112 which corresponds to the port 40 in the previously described embodiment and the supporting block 110 is formed with three spaced ports from which ducts 56, 5l'u and 58a respectively extend. The duct 5'!a extends into operative relationship with the port 3i of the valve member i11; the duct 58a extends into operative relationship with the port 32' in said valve member 711; and the duct 5'6a extends to a duct 591- one of whose ends enters the chamber k2 of the valve unit K5 and the other Aof whose ends enters the block 9'10 into operative relation with the valve 711.

The preparatory valve moans H, the several valve units K-Ks, inclusive, the casings B and C, the pistons B' andvC' and the connections be- "tween said pistons and the member a of the The only addiviously described embodiment but is connected by a stem m12 with 'a piston m13 which operates within a casing m1* separate from the casing m1s in which the valve operates. The pump M1 and the chamber `M5` of the previous embodiment are employed in this particular embodiment and are connected with each other and with the piston chamber m14 through ducts 45', M', 46" and I1 arranged as shown to correspond in function with the ducts which connect the pump, chamber m and chamber m5 with each other in the previously described embodiment. In this particular embodiment the needle valve, marked 48', is mounted in the duct 41' which connects the ducts 44' and 4'6' with each other.

Duets, herein marked il0',` respectively corresponding to the ducts I-IO of the previously described embodiment are employed in this embodiment, but their correlations with the valve 7'11 and the valve m11 have been changed somewhat. Thus. it will be noticed that the ends of the ducts 4', 6', 8' and i0' opposite the valve h1 enter the member 9'10 at places whichcause said ends to be-closed when the valve j is in its neutral position, shown in Fig. 15, and to be opened (by the ports 30', 3I'f, 32' and 33') when said valve has been moved to the position it occupies during the shifting operations. It will also be noticed that the duct 1' has two branches 'la and 1b, that the duct 3' and the branch duct .1 have communication with each other when the valve member m1l is in its initial position. that the duct 9 has two branches, respectively marked 9&1 and 982, and that the duct 5' is so arranged with relation to said branch duct 9&2 is to have communication with the latter through the port 4|' when the valve m11 is in its position for shifting into second gear and that the branch ducts 1b and Snare so arranged as to have communication with -each other through said port 4i' when the valve member m11 is in its position for shifting into high" gear.

It will. further be noticed that when the parts are in the said neutral position the port 30' of the valve :1'11 is in communication with the chamber k2 of the valve unit K1 through a duct 5l' and that the chamber lc'of said valve unit (K1) has communication with the atmosphere through its port 22 and with the end portion 0** of the casing or cylinder, C through a duc*J 63'; that the port 3|' of said valve 711 has communication with the valved control means L1o through the duct 5la and with the chamber k2 of the valve unit K2 through duct 52 and that the chamber 1c of said valve unit (K2) has communication with the atmosphere through its port 22 and with the end portion'b* of the casing or cylinder B through the duct that the port 32' of said valve 7'11 has communication with said valved control means L10 through the duct 58 and with the chamber k2 of the valve unit K3 through the duct 53' and that the chamber lc of said valve unit (K3) has communication with the atmosphere through its port '22 and with the end portion b" of the casing or cylinder B through duct '6i'; that the port 33' of said valve 7'11 has communication with the chamber k2 o f the valve unit K1 through the 'duct 54 and the chamber 1c of said valve unit (K4) has communication with thc atmosphere through its port 22 and the end portion c* of thecaslng or cylinder C through the duct 62'; and that the 

